The present invention relates to a novel flashlight head construction. More specifically, this invention relates to a flashlight head construction wherein the lighting elements of the flashlight are each individually isolated and contained in separate reflector cups to provide protection for the lighting elements and to facilitate the sealing of the flashlight head.
Flashlights of varying sizes and shapes are well known in the art. A number of such designs are known that utilize two or more batteries as their source of electrical energy, carried in series in a tubular body, where the tubular body also serves as a handle for the flashlight. Typically, an electrical circuit is established from one terminal of the battery, through a conductor to an external switch and then through another conductor to one contact of a bulb. After passing through the filament of the bulb, the electrical circuit emerges through a second contact of the bulb in electrical contact with a conductor, which in turn is in electrical contact with the flashlight housing. The flashlight housing provides an electrically conductive path to the other terminal at the rear of the battery. Actuation of the external switch completes the electrical circuit enabling electrical current to pass through the filament of the bulb, thereby generating light that is then typically focused by a reflector to form a beam of light.
In general, these flashlight switch mechanisms operate in two basic manners. The first mechanism is a pushbutton type switch on the side or bottom of the light. The user depresses the switch, which locks into the engaged position, turning the flashlight on. To turn the light off, the user again depresses the switch, unlocking it and turning the light off. Often, if a watertight seal is desired, a rubberized material is installed into the body of the flashlight as a covering over the switch mechanism. This design has several drawbacks. One drawback is that the increased number of parts creates additional assembly steps and increases the difficulty of assembly process. Another drawback is the possibility of leaks developing as the rubber membrane wears out from the stretching action resulting from continuous use.
In an attempt to resolve the drawbacks noted above with respect to the push-button type switches, a second type of rotatable switch was developed for in-line use in flashlights. In one design, an end cap is rotatably secured to the flashlight body. To establish the required electrical contact, the end cap is rotated making contact to illuminate the lamp bulb. A number of such prior art designs feature rotatable end caps which are rotated to move the batteries longitudinally within the flashlight body towards the lamp bulb, thereby causing contact between the battery contact and the base contact of the lamp bulb. In the open position, the battery is typically spring biased away from the base contact of the bulb.
In other designs, miniature flashlights have been designed where the rotatable switch is located in the reflector end of the flashlight body. The lamp bulb is located within an insulated receptacle at the reflector end of the flashlight with one or more conductive pins being rotatably aligned by movement of the switch portion of the device to establish electrical contact. While these switch mechanisms are internal to the device and thus less subject to damage, they are overly complicated in design and more costly to manufacture and require higher assembly tolerances.
In addition, the types of switches described above all generally operate in a forward direction, meaning that as the user turns the head or tail of the flashlight, tightening it onto the body of the flashlight, switch contact is eventually made thereby turning the flashlight on. Electrical contact, in this type of switch, is achieved by bringing a spring contact on the inside of the flashlight into contact with one pole of the battery contained within the body. These types of switches are problematic because the components of the flashlight are not always firmly holding the batteries in place. For example, when the flashlight is in the off position, the head is generally partially unscrewed from the body of the flashlight, preventing the spring on the back of the head from contacting the battery. This arrangement, however, also prevents the battery from being restrained, allowing the battery to freely float within the flashlight body. In addition, the range of switch contact is very limited, thus providing a very low tolerance switch mechanism that does not operate smoothly.
There is also further difficulty in providing a seal for prior art flashlights that attempt to incorporate several LED lighting elements in an array. Generally, this type configuration is placed into a traditional parabolic reflector cup with multiple holes provided in the rear thereof. In these cases, multiple lighting sources are being provided at several locations within the reflector cup. Since reflectors of this type are specifically designed to capture and direct light from a single point source located at or near their optical center, their operation with several off axis light sources is less than desirable. The method of sealing this type of assembly is typical in the prior art where a lens is provided between two gasket elements. In this assembly, the flashlight head, lens and gaskets are all susceptible to damage that could lead to leakage and failure of the flashlight.
It is therefore and object of the present invention to provide an improved flashlight assembly that is entirely self contained and completely waterproof. It is a further object of the present invention to provide a head assembly for a flashlight that has improved operating characteristics, such as enhanced light reflection and an integrally sealed construction. It is yet another object of the present invention to provide an in-line flashlight assembly that is completely enclosed within the body of a flashlight thereby eliminating the possibility of contamination and damage from external forces while containing the lighting elements in individual reflector cups.